21 TIME REM
01:58
If y varies directly as x, and y is 180 when x is n and y is n when x is 5, what is the value of n?
6
18
30
36

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.